Cutting blades find a great number of applications in industry, (for example, cutting blades utilized in the production of gears).
The shape of cutting blades vary greatly. Different blade geometries are usually required to produce gears of different geometries. A cutting blade may have several different surfaces which effect the particular shape, size and location of the blade profile which, in turn, may influence the shape of the cut gear. Examples of these surfaces are cutting side, clearance side, shoulder, and edge radius.
The most common method to produce a specified shape on the surface of a blade is form grinding. In this method the inverse shape of the blade surface is dressed (formed) into a grinding wheel and then the grinding wheel is plunge fed into the blade. The shape of the blade is controlled by a dresser, usually a diamond tipped tool, that is capable of dressing (forming) the required range of shapes into a grinding wheel face. An example of a dressed grinding wheel is illustrated by British Patent Specification 696,804 which shows a wheel having a flat active grinding surface. This surface would produce a planar surface on a cutting blade, the orientation of the planar surface being dependent upon the angle in which the blade is traversed across the grinding wheel surface.
In order to form more than one surface shape on a blade a plurality of dressed grinding wheels have been used as shown by U.S. Pat. Nos. 1,285,124, 2,410,348, 2,629,973 and 4,265,053. Each grinding wheel forms one surface on a blade.
Another approach has been to use a grinding wheel with more than one profile dressed into it as disclosed by U.S. Pat. No. 3,881,889. The grinding wheel in this disclosure comprises two separate grinding surfaces.
A somewhat different approach has been to utilize a template or cam as a guide to dictate the path of a grinding wheel across the surface of a cutting blade as seen in U.S. Pat. Nos. 3,538,649 and 4,163,345 respectively.
The use of a single profiled wheel to form desired surfaces on opposite sides of a blade is shown by U.S. Pat. No. 2,346,865. However, the cutting profiles are of the same shape, thus requiring only one shape to be dressed into the grinding wheel, and the blade must be reversed in its holding block in order to form both profiles.
A more recent approach has been the generating of surfaces on a blade. U.S. Pat. No. 4,170,091 shows a plurality of cutting blades secured in a tool-holding ring. The ring is rotated and the top portion of the blades is brought into contact with a rotating grinding wheel to form a topland surface. The tool-holding ring is then pivoted while the blades are in contact with the grinding wheel. This results in a rounded corner being generated between the topland and a side surface. The continued pivoting of the ring results in contact of the side surface of the blades with the grinding wheel thereby forming the desired shape on the side surface. The ring is turned completely over and the process is then repeated for the opposite side of the blades. However, the grinding wheel in this process must still be dressed with a particular profile capable of forming the desired shape on the side surfaces of the blades.
The grinding machine of U.S. Pat. No. 4,186,529 comprises up to ten computer numerically controlled (CNC) axes. These axes permit the grinding wheel and the cutting blade to be moved relative to one another and be brought into engagement with one another at almost any desired angular relation necessary for the grinding of the blade surfaces. A preferred grinding wheel is shaped in the form of a saucer having a conical shaped grinding surface. The disclosure further states that the shape of the grinding wheel will depend upon the shape of the product to be ground.